1. Field of the Invention
The present invention relates to a trouble sensing device of mechanical driving mechanisms driven by supplying driving current.
2. Description of the Related Art
Motors, solenoids, clutches, fans for cooling, and the like are mechanical driving mechanisms driven by supplying driving current and these are provided at an image forming device, a copier, or the like.
When there is trouble with these driving mechanisms, it is necessary to detect the trouble of each part of the mechanisms.
Conventionally, the following was proposed as a method for diagnosing trouble: a polygon motor, a solenoid, and a clutch are each driven independently under instructions from a CPU. The currents supplied to the respective drivers and motors and the like are sensed by the potential differences at the both ends of the resistors, and the current values which are sensed are monitored at the CPU. On the basis of inputted voltage values, the CPU carries out trouble diagnosis of the polygon motor, the solenoid, and the clutch (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2001-228056).
Carrying out trouble sensing of a part as follows has also been proposed: a reference current, which shows that a given, specific part is functioning correctly, is stored in a computer memory. While only that specific part is consuming current, the current which is supplied to an image forming device which includes that specific part is read. The read current value and the reference current stored in the memory are compared, and trouble sensing of the part is carried out in accordance with whether the read current value matches the reference current (see, for example, JP-A No. 2003-228419).
However, in accordance with the aforementioned technique disclosed in JP-A No. 2001-228056, each part must be operated one-by-one in order to measure the currents of the respective parts. There is therefore the problem that a specific inspection mode or trouble diagnosing mode must be implemented.
There is also the problem that a very long time is needed in order to operate each part one-by-one, and the period of time over which the user cannot utilize the image forming device (the down time) is long.
Further, in the technique disclosed in JP-A No. 2003-228419, the trouble sensing can be carried out while the user is using the device. Therefore, although the problem of down time for trouble sensing arising does not occur, the trouble sensing cannot be carried out unless there is a state in which only the specific (one) part is being operated. Therefore, there is the problem that trouble sensing is hardly carried out at all in devices, such as image forming devices, in which, when the start button is pressed, plural parts immediately carry out operation almost simultaneously.